1. Field of the Invention
The present invention relates to a piezoelectric actuator, a lens barrel, and an imaging device.
Priority is claimed on Japanese Patent Application No. 2010-220426, filed Sep. 30, 2010, the content of which is incorporated herein by reference.
2. Description of Related Art
A piezoelectric actuator is known in which a driving target member is driven by driving plural piezoelectric elements to cause tip members coming in contact with the driving target member to move elliptically (for example, see JP-A-2007-236138). In the piezoelectric actuator described in JP-A-2007-236138, when an XYZ orthogonal coordinate system is set up, the driving target member is driven in the X axis direction by the elliptical movement of the tip members parallel to the XZ plane.
However, the traditional piezoelectric actuator has a problem in that the vibration in the lifting direction in which the distance between a tip member and a base member varies and the vibration in the feed direction in which the distance between the tip member and the base member does not vary cannot be independently controlled. There is also a problem in that it is difficult to cause the tip member to efficiently vibrate in the lifting direction and in the feed direction.